Methods and apparatus for borehole-corrected spectral analysis of earth formations
US4661701A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1985 |
| Grant date | Apr 28, 1987 |
| Priority date | — |
| Expiry date | Jul 17, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V5/101
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Capture gamma ray spectroscopy measurements of earth formations traversed by a borehole are corrected for the influence thereon of the geometry and constituents of the borehole, thereby affording more accurate measurements of the spectral contributions from the formation elements. A partition factor is determined for each separate homogeneous region in the borehole/formation measurement environment, i.e., the tool, the borehole fluid, the casing (if present), the cement annulus (if present), and the formation, and these factors are plugged into predetermined elemental yield relationships, for the elements for which capture spectral measurements are made, to determine the volumetric fractions of such elements (or minerals containing such elements) in the formation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.